The present invention relates in general to gas leak detectors, and, in particular, to a water sensitive probe valve that automatically closes a path to a gas indicator upon sensing the presence of water, to thus protect the gas indicator.
Gas leak detectors or gas indicators are used to detect leaks from gas mains and the like. In general, the type of leak detector of concern here has an elongated probe coupled to a gas indicator through a line. Gas passes through the probe and line into a gas indicator. Typically these instruments are hand operated. Water can damage the gas indicator.
Water can be drawn up to the gas indicator through the probe and cause damage.
It is highly desirable, then, to provide some means to prevent water from entering the gas indicator and damaging that indicator.
Water soluble devices have been used as safeties to close a passage when water is present, but those devices are awkward to use and arm.
Gas leak detectors must be periodically serviced to change filters used to protect the gas indicator from particulates. A requirement for disassembly of the gas leak detector for such service should not be hampered by any means to protect the gas indicator from water.
U.S. Pat. No. 3,472,253 discloses a water detector and valve shutoff that uses a spacing element loaded in compression by a valve element. The element fails when soaked in water. A nut must be removed and an entire assembly broken down to rearm the device. U.S. Pat. No. 2,798,503 to Carver et al discloses a tension loaded water soluble link only as a safety shutoff for hot water heaters. The safety is remote from the valve.